Heroin addiction in African Americans: a hypothesis-driven association study

Heroin addiction is a chronic complex disease with a substantial genetic contribution. This study was designed to identify gene variants associated with heroin addiction in African Americans. The emphasis was on genes involved in reward modulation, behavioral control, cognitive function, signal transduction and stress response. We have performed a case-control association analysis by screening with 1350 variants of 130 genes. The sample consisted of 202 former severe heroin addicts in methadone treatment and 167 healthy controls with no history of drug abuse. Single nucleotide polymorphism (SNP), haplotype and multi-SNP genotype pattern analyses were performed. Seventeen SNPs showed point-wise significant association with heroin addiction (nominal P< 0.01). These SNPs are from genes encoding several receptors: adrenergic (ADRA1A), arginine vasopressin (AVPR1A), cholinergic (CHRM2), dopamine (DRD1), GABA-A (GABRB3), glutamate (GRIN2A) and serotonin (HTR3A) as well as alcohol dehydrogenase (ADH7), glutamic acid decarboxylase (GAD1 and GAD2), the nucleoside transporter (SLC29A1) and diazepam-binding inhibitor (DBI). The most significant result of the analyses was obtained for the GRIN2A haplotype G-A-T (rs4587976-rs1071502-rs1366076) with protective effect (P(uncorrected) = 9.6E- 05, P(corrected) = 0.058). This study corroborates several reported associations with alcohol and drug addiction as well as other related disorders and extends the list of variants that may affect the development of heroin addiction. Further studies will be necessary to replicate these associations and to elucidate the roles of these variants in drug addiction vulnerability.

Genetic susceptibility to heroin addiction: a candidate gene association study

Heroin addiction is a chronic complex disease with a substantial genetic contribution. This study was designed to identify genetic variants that are associated with susceptibility to develop heroin addiction by analyzing 1350 variants in 130 candidate genes. All subjects had Caucasian ancestry. The sample consisted of 412 former severe heroin addicts in methadone treatment, and 184 healthy controls with no history of drug abuse. Nine variants, in six genes, showed the lowest nominal P values in the association tests (P < 0.01). These variants were in noncoding regions of the genes encoding the mu (OPRM1; rs510769 and rs3778151), kappa (OPRK1; rs6473797) and delta (OPRD1; rs2236861, rs2236857 and rs3766951) opioid receptors; the neuropeptide galanin (GAL; rs694066); the serotonin receptor subtype 3B (HTR3B; rs3758987) and the casein kinase 1 isoform epsilon (CSNK1E; rs1534891). Several haplotypes and multilocus genotype patterns showed nominally significant associations (e.g. OPRM1; P = 0.0006 and CSNK1E; P = 0.0007). Analysis of a combined effect of OPRM1 and OPRD1 showed that rs510769 and rs2236861 increase the risk of heroin addiction (P = 0.0005). None of these associations remained significant after adjustment for multiple testing. This study suggests the involvement of several genes and variants in heroin addiction, which is worthy of future study.

Attention-deficit/hyperactivity disorder in adult patients with posttraumatic stress disorder (PTSD): is ADHD a vulnerability factor?

OBJECTIVE

There is limited evidence suggesting a link between posttraumatic stress disorder (PTSD) and Attention-Deficit/ Hyperactivity Disorder (ADHD). This study examined the association between PTSD and ADHD using retrospective and current clinical evaluations.

METHOD

Twenty-five male veterans with PTSD and 22 male veterans with panic disorder were evaluated for ADHD. The data was analyzed using chi-square and student's t-tests.

RESULTS

Thirty-six percent of participants with PTSD and 9% of participants with panic disorder met criteria for childhood ADHD. Twenty-eight percent of participants with PTSD and 5% of participants with panic disorder met criteria for current ADHD.

CONCLUSIONS

There appears to be a significant association of PTSD with ADHD. ADHD or common predisposing factors may increase the vulnerability for developing PTSD.

Differential effects of dopamine antagonists on locomotor activity, conditioned activity and conditioned place preference induced by cocaine in rats

Neuronal substrates that mediate the conditioned effects of cocaine have not been well characterized. To examine dopaminergic mechanisms, three antagonists were tested for their capacity to inhibit the expression of conditioned locomotor activity and conditioned place preference in rats. Antagonists were also assessed against acute cocaine-stimulated locomotor activity for comparison. For locomotor activity conditioning, six conditioning sessions were conducted over a 10-day period. Paired rats received 10 mg/kg cocaine prior to activity sessions and saline after; unpaired controls received saline prior and cocaine after. For place preference conditioning, eight conditioning sessions were conducted over a 13-day period; rats received 10 mg/kg cocaine while restricted to one of two distinct chambers and, on alternate days, they received saline in the other. Antagonists (haloperidol, raclopride and SCH23390; 0.03-0.1 mg/kg) were given only on test days for conditioned effects. All three antagonists significantly and dose-dependently attenuated the direct stimulatory effect of cocaine. SCH23390 showed a tendency to reduce the expression of conditioned locomotor activity, and only haloperidol blocked the expression of conditioned place preference. Thus, direct and conditioned stimulant effects of cocaine were shown to be differentially sensitive to dopamine receptor blockade. Further, conditioned stimulant effects differed from conditioned reinforcing effects in this regard.

Effects of smoking on acoustic startle and prepulse inhibition in humans

RATIONALE

Prepulse inhibition of the acoustic startle response (PPI) is a paradigm in which a startle response to an auditory stimulus is reduced when that stimulus is preceded by a lower intensity, non-startling stimulus (prepulse). PPI is used as an operational measure of sensorimotor gating in both humans and other mammals. Acute administration of nicotine enhances PPI in rats, an effect that has been recently demonstrated in humans.

OBJECTIVES

We compared PPI in 12 male smokers and 14 male non-smokers tested in four repeat startle sessions across 2 test days in order to examine further the effects of smoking and smoking withdrawal on acoustic startle and PPI.

METHODS

In a crossover design, the smokers smoked ad lib or abstained from smoking overnight prior to 9 a.m. testing. These 2 test days were in randomized order. On both days, smokers were immediately retested after smoking three cigarettes. Non-smokers were tested twice on each of 2 separate days.

RESULTS

Across sessions, the smokers had reduced startle to pulse alone stimuli in the first block of each session when compared to the non-smokers. The non-smokers had no change in gating across their four test sessions. For the smokers, the abstinence condition produced a non-significant reduction in PPI compared to that of the ad lib smoking day. During the smoking abstinence session, smokers had comparable gating to non-smokers. Smoking immediately after washout produced a significant improvement in PPI such that gating in the smokers exceeded that of the non-smokers.

CONCLUSION

Smoking after overnight washout from cigarettes enhanced sensorimotor gating compared to pre-smoking values and compared to gating in non-smokers.

Evidence that L-deprenyl treatment for one week does not inhibit MAO A or the dopamine transporter in the human brain

In this study, we investigated whether treatment with L-deprenyl, a selective monoamine oxidase B (MAO B) inhibitor, also inhibits MAO A or the dopamine transporter in the human brain. Six normal volunteers (age 46+/-6 yrs) had two PET sessions, one at baseline and one following L-deprenyl (10 mg/day) for 1 week. Each session included one scan with [11C]clorgyline (to assess MAO A) and one scan 2 hours later with [11C]cocaine (to assess dopamine transporter availability). A 3-compartment model was used to compare the plasma-to-brain transfer constant, K1 (a function of blood flow) and lambdak3 (a kinetic term proportional to brain MAO A) before and after treatment. Dopamine transporter availability was measured as the ratio of distribution volumes of the striatum to cerebellum (DVR) which is equal to Bmax/KD +1. L-Deprenyl treatment for 1 week did not affect either brain MAO A activity or dopamine transporter availability. There was a non-significant trend for an increase in K1 after L-deprenyl. These results confirm that L-deprenyl after one week of treatment at doses typically used clinically is selective for MAO B and that it does not produce a measurable affect on the dopamine transporter, suggesting that MAO A inhibition and dopamine transporter blockade do not contribute to its pharmacological effects.

Prepulse inhibition of the acoustic startle response in cocaine-withdrawn rats

Prepulse inhibition (PPI) of startle is a sensorimotor gating task in which a low-intensity acoustic stimulus presented prior to a high-intensity, startle-eliciting stimulus can attenuate the acoustic startle response (ASR). Previous studies on startle reactivity in cocaine-withdrawn rats have found minimal changes; the present study extends this work to the gating of ASR. In Experiment 1, rats were injected daily with either saline or cocaine (30 mg/kg i.p.) for 2 weeks. ASR and PPI were measured prior to, and at 3- and 14-day withdrawal from, the chronic treatment. No effect of cocaine treatment was found on either measure. In Experiment 2, treatment was extended to 8 weeks, and an earlier withdrawal time point (1 day) was added. Rats treated with cocaine for 8 weeks exhibited lower startle reactivity during withdrawal compared with saline-treated controls. PPI did not differ between treatment groups. Thus, extended chronic treatment with cocaine rendered significant effects on startle responsivity. Further, this finding mirrors the blunted ASR exhibited in chronic cocaine users [Neuropsychopharmacology 22 (2000) 89.].

Fine volumetric analysis of the cerebral ventricular system in schizophrenia: further evidence for multifocal mild to moderate enlargement

We used traditional volumetric regional analysis and a finer anterior-posterior (AP) profile volumetric analysis to examine the cerebral ventricular system in an all-male, demographically matched sample of schizophrenia patients (n = 73) and normal controls (n = 29) using 2.8-mm-thin coronal T1-weighted magnetic resonance images from a 1.5 tesla scanner. Traditional regional analysis was performed on various regions using absolute volumes after adjusting for intracranial volume (ICV) and age. The fine AP profile analysis was done by intrasubject "stacking" of contiguous coronal cross-sectional volumes (adjusted for ICV and age) across the AP plane, intersubject AP alignment of all slices relative to the mammillary bodies, and plotting of slice volumes along the AP plane with 95 percent t-test-based confidence intervals. Schizophrenia subjects had mild to moderate multifocal ventricular enlargement (overall effect size d = 0.48), which was especially prominent in the right posterior temporal horn and, more generally, in the central to posterior portions of the lateral and third ventricles. Schizophrenia subjects also had milder enlargement in the left frontal horn, but no significant differences were found in the anterior temporal horns and the right frontal horn. Post hoc analyses of demographic, clinical, and neuropsychological variables did not account for much variance in the ventriculomegaly observed in the schizophrenia group. The lack of a single locus in the observed ventricular enlargement, the nonsignificant results from schizophrenia subtypes based on regional distributions, and the strong positive correlations among the ventricular regions for the schizophrenia group suggest that the ventriculomegaly seen in this chronic population reflects a single brainwide disease process leading to a multifocal or patchy loss of integrity in brain structure.

Conditioned locomotor stimulant effects of cocaine in rats do not result from interference with habituation

RATIONALE

Classical conditioning has been proposed to account for the hyperactivity observed in drug-free rats when placed in an environment previously paired with cocaine administration. However, an alternative explanation is that hyperactivity results from an inability of rats to habituate to the environment under the influence of cocaine.

OBJECTIVES

In this study, preconditioning exposure to the test environment was increased from one session (standard procedure) to seven (modified procedure) to test the "antihabituation" hypothesis.

METHODS

After preconditioning exposure, six conditioning sessions took place over a 10-day to 13-day period. Paired rats received 10 mg/kg cocaine i.p. prior to activity sessions and saline i.p. upon return to the colony room. Unpaired rats received saline prior to and cocaine after activity sessions. Time-off rats were withheld from the activity boxes, but were subject to all other procedures during conditioning. On the test day, all rats received saline prior to activity sessions.

RESULTS

In the standard procedure, paired rats exhibited significantly greater activity than unpaired rats on the test day, consistent with previous reports. In the modified procedure, mean activity (all rats) decreased between the first and last preconditioning sessions. Still, the paired group exhibited greater activity than the unpaired group on the test day, suggesting that a conditioned stimulant effect developed in habituated rats. Activity in the time-off group did not significantly differ from the unpaired group demonstrating the habituation had not dissipated over this time period.

CONCLUSIONS

These results support the conclusion that hyperactivity observed on the test day was not a result of antihabituation effects of cocaine.

Volumetric measure of the frontal and temporal lobe regions in schizophrenia: relationship to negative symptoms

BACKGROUND

Previous research has provided evidence for brain abnormalities in schizophrenia, but their relationship to specific clinical symptoms and syndromes remains unclear.

METHODS

With an all-male demographically similar sample of 53 schizophrenic patients and 29 normal control subjects, cerebral gray and white matter volumes (adjusted for intracranial volume and age were determined for regions in the prefrontal lobe and in the superficial and mesial temporal lobe using T1-weighted magnetic resonance imaging with 2.8-mm coronal slices.

RESULTS

As a group, schizophrenic patients had wide-spread bilateral decrements in gray matter in the pre-frontal (7.4%) and temporal lobe regions (8.9%), but not in white matter in these regions. In the temporal lobe, gray matter reductions were found bilaterally in the superior temporal gyrus (6.0%), but not in the hippocampus and parahippocampus. While there were no overall group differences in white matter volumes, widespread decrements in prefrontal white matter in schizophrenic patients (n = 53) were related to higher levels of negative symptoms (partial r[49] = -0.42, P = .002), as measured by the Scale for the Assessment of Negative Symptoms. A post hoc analysis revealed that schizophrenic patients with high negative symptoms had generalized prefrontal white matter reductions (11.4%) that were most severe in the orbitofrontal subregion (15.1%).

CONCLUSIONS

These results suggest that gray matter deficits may be a fairly common structural abnormality of schizophrenia, whereas reductions in prefrontal white matter may be associated with schizophrenic negative symptoms.

Vitamin E treatment for tardive dyskinesia. Veterans Affairs Cooperative Study #394 Study Group

BACKGROUND

Several short-term, controlled trials have documented the efficacy of vitamin E in treating tardive dyskinesia. However, the persistent nature of the disease prompted us to perform a multicenter, longer-term trial of vitamin E.

METHODS

The study was a prospective, randomized, 9-site trial of up to 2 years of treatment with d-vitamin E (1600 IU/d) vs matching placebo. One hundred fifty-eight subjects with tardive dyskinesia who were receiving neuroleptic medications were enrolled. The blinded assessments performed were clinical (Abnormal Involuntary Movements Scale, Barnes Akathisia Scale, and Modified Simpson-Angus [for Extrapyramidal Symptoms] Scale) and electromechanical assessments of movement disorders, psychiatric status (Brief Psychiatric Rating Scale), and functioning (Global Assessment of Functioning). There were no significant differences in baseline demographic characteristics or in study assessments between the group that received vitamin E and the group that received placebo.

RESULTS

Vitamin E was well tolerated and subject compliance with medication was good and similar between treatment groups. One hundred seven subjects (70% of those receiving vitamin E and 66% of subjects receiving placebo) completed at least 1 year of treatment. There were no significant effects of vitamin E on total scores or subscale scores for the AIMS, electromechanical measures of dyskinesia, or scores from the other 4 scales.

CONCLUSION

This long-term, randomized trial of vitamin E vs placebo found no evidence for efficacy of vitamin E in the treatment of tardive dyskinesia.

Structural magnetic resonance image averaging in schizophrenia

OBJECTIVE

Intersubject averaging of structural magnetic resonance (MR) images has been infrequently used as a means to study group differences in cerebral structure throughout the brain. In the present study, the authors used linear intersubject averaging of structural MR images to evaluate the validity and utility of this technique and to extend previous research, conducted using a different approach to image averaging, in which reduction in thalamic size and abnormalities in perithalamic white matter tracts in the brains of schizophrenic patients were reported by Andreasen et al.

METHOD

A 1.5-T MR scanner was used to obtain high-resolution, whole brain T1-weighted structural MR images for an age-matched sample of 25 schizophrenic patients and 25 normal control subjects. A "bounding box" procedure was used to create a single "averaged" brain for the schizophrenic group and for the control group. Differences in signal intensity between the two average brains were examined on a pixel-wise basis through use of one-tailed effect size maps.

RESULTS

Effect size maps revealed widespread patchy signal intensity differences between the two groups in both cortical and periventricular areas, including major white matter tracts. The signal intensity differences were consistent with cortical thinning/sulcal widening and ventricular enlargement. No differences were found within thalamus or in immediately surrounding white matter. Effect size maps for differences (schizophrenic minus normal subjects) had only small values.

CONCLUSIONS

These results are consistent with diffuse structural brain abnormalities of both gray and white matter in schizophrenic populations such as the one in this study.

Long-term treatment effects of vitamin E for tardive dyskinesia

BACKGROUND

Several studies have found that alpha-tocopherol (vitamin E) can effectively treat tardive dyskinesia (TD). A limitation of these trials is their short treatment durations (maximum of 12 weeks), which do not allow us to address the effects of long-term treatment.

METHODS

To participate, patients had to have TD and be on stable oral medications. The study enrolled 40 patients who received up to 36 weeks of treatment with d-vitamin E (1600 IU per day) or placebo.

RESULTS

Using the Abnormal Involuntary Movements Scale (AIMS) score (sum of items #1-7) to measure TD severity, the study found a significant difference (3 points) in mean AIMS scores, in favor of vitamin E, starting at 10 weeks of treatment and continuing through the full 36 weeks. We used linear mixed-effects regression to quantify the impact of several covariates, and found that treatment assignment. TD duration, and chlorpromazine equivalents had significant effects on decreasing the AIMS score.

CONCLUSIONS

The study's finding that vitamin E is effective in treating TD agrees with results from prior studies and provides evidence that the effect may extend to treatment of up to 36 weeks. These findings are in direct contrast to those of VA Cooperative Study #394, a much larger, long-term, multi-site study, conducted by many of the same investigators, in which Vitamin E was not superior to placebo.

Reliability of an instrumental assessment of tardive dyskinesia: results from VA Cooperative Study #394

Nine VA Medical Centers are participating in a 2-year double-blind placebo controlled study of antioxidant treatment for tardive dyskinesia (TD) conducted by the Department of Veteran Affairs Cooperative Studies Program. One of the principal outcome measures of this study is the score derived from the instrumental assessment of upper extremity dyskinesia. Dyskinetic hand movements are quantified by assessing the variability associated with steady-state isometric force generated by the patient. In the present report, we describe the training procedures and results of a multi-center reliability assessment of this procedure. Data from nine study centers comprising 45 individual patients with six trials each (three from left hand and three from right hand) were reanalyzed by an independent investigator and the results were subjected to reliability assessment. For the statistic of interest (average coefficient of variation over trials 2 and 3 for each hand, then take the larger of these two values), we found very high intraclass correlation coefficients for reliability over all patients across sites (ICC = 0.995). We also calculated the reliability of the measures across trials within patient for each combination of hand (right, left, dominant), rater group (site, control), and trials set (all three, trials 2 and 3). For a given hand and trial set, the reliability of the site raters was similar to that of the control. This study demonstrates that instrumental measures for the assessment of dyskinesia are reliable and can be implemented in multi-center studies with minimal training.

Interrater reliability issues in multicenter trials, Part II: Statistical procedures used in Department of Veterans Affairs Cooperative Study #394

The primary goal of Veterans Affairs (VA) Cooperative Study (CS) #394 is to determine if vitamin E is a safe and efficacious treatment for tardive dyskinesia (TD). The study uses various instruments to assess subjects for movement disorders (Abnormal Involuntary Movement Scale [AIMS], and Barnes Akathisia Scale [BAS]), psychopathology (Anchored Brief Psychiatric Rating Scale [BPRS]), and level of functioning (Global Assessment of Functioning scale [GAF]). Since the study involves nine sites, each with its own set of raters, it is important to establish and maintain high interrater reliability (IRR) on these instruments throughout the study and to identify raters who differ significantly from the others. To make this determination, personnel at each site assessed subjects from standardized videotapes on the AIMS, BAS, and Anchored BPRS, and rated written vignettes on the GAF. We fit these data to a two-way additive model to identify nonstandardized raters (i.e., those whose average ratings were significantly lower or higher than the others, or those whose scores, after adjusting for subject and rater effects, were highly variable). The proportion of nonstandardized raters ranged from 7 percent (Anchored BPRS) to 33 percent (AIMS). The estimated intraclass correlation coefficients (ICCs) indicated moderate reliability for the AIMS, BAS, and Anchored BPRS (0.73 to 0.75) and excellent agreement for the GAF (0.90). The companion article (Part I: Tracy et al. 1997, page 53 of this issue) describes the procedures used to train the raters for this study.

Interrater reliability issues in multicenter trials, Part I: Theoretical concepts and operational procedures used in Department of Veterans Affairs Cooperative Study #394

This article describes a standardized method for establishing and maintaining desired levels of interrater reliability (IRR) in multicenter trials. The procedure involves six steps: distribution of procedural guides, distribution of an introduction tape, initial distribution of patient interviews to rate, training at the study kickoff meeting, ongoing IRR monitoring, and group training throughout the study. This method is being used in a national Veterans Affairs Cooperative Study (CS #394), involving nine sites to examine the treatment effects of vitamin E on tardive dyskinesia. The six-step standardized process allowed for early detection of areas of concern in assessment administration. When comparing intraclass correlation coefficients (ICCs) at different points in the initial training, the Barnes Akathisia Scale and Anchored Brief Psychiatric Rating Scale reliability improved from 0.68 to 0.74 and from 0.54 to 0.87, respectively. After analyzing the ratings collected prior to the start of CS #394, data were collected to conduct the first check on Abnormal Involuntary Movement Scale (AIMS) IRR during enrollment; the estimated ICC for the AIMS had decreased from 0.87 to 0.60. Raters were instructed to re-assess the subjects from the first videotape on the AIMS and received additional training. The re-rating indicated very good reliability, 0.84, IRR was measured once for the Global Assessment of Functioning Scale resulting in an ICC of 0.90. The companion article (Part II: Edson et al. 1997, page 59 of this issue) describes the statistical procedures used to measure IRR.

Antioxidant treatment of tardive dyskinesia

Tardive dyskinesia (TD) is a frequently occurring side effect of treatment with neuroleptic antipsychotic drugs. TD is a persistent and often irreversible syndrome characterized by abnormal movements, including lingual and orofacial dyskinesia, grimacing, tics, choreic movements of the limbs and trunk, and athetosis and dystonia. In some patients the muscles of respiration and speech may also be involved. There is no established treatment for TD.

Amphetamine and negative symptoms of schizophrenia

The purpose of this study was to assess further the effect of amphetamine on negative symptoms of schizophrenia. Thirty-seven schizophrenic males meeting DSM-III criteria were rated with the Brief Psychiatric Rating Scale, the Abrams and Taylor Scale, and the Abnormal Involuntary Movements Scale before and after double-blind administration of either amphetamine (n = 26) or placebo (n = 11). Our results indicated that amphetamine administration generally did not improve negative symptoms, even when accounting for changes in positive symptoms. However, greater baseline negative symptoms were associated with a modest diminution after amphetamine treatment. Therefore, amphetamine may modestly improve negative symptoms in those schizophrenics in whom this symptomatology is more severe.

Persistent psychosis after reduction in pre- and post-synaptic dopaminergic function

The purpose of this study was to evaluate the hypothesis that neuroleptic non-response in the face of "adequate" DA post-synaptic receptor blockade reflects failure of regulatory mechanisms to decrease DA pre-synaptic activity. Eight chronic schizophrenics, meeting rigorous criteria for neuroleptic non-response, were treated for four weeks with alpha-methylparatyrosine as an adjunct to their previously stable neuroleptic dose. Treatment with AMPT produced a prompt decrease in plasma HVA that was, on average, 72% lower at the end of the study. While there was also strong clinical evidence of reduction in central dopaminergic activity (both a significant reduction in dyskinetic movements and increase in extrapyramidal symptoms), there was virtually no change in severity of psychotic symptoms. Thus, in this group of non-responders, psychotic symptoms persisted despite both extensive dopamine post-synaptic receptor blockade and marked reduction of presynaptic activity. These symptoms may not be directly DA dependent.

Elevated PLA2 activity in schizophrenics and other psychiatric patients

We measured serum phospholipase A2 (PLA2) activity in 39 schizophrenics, 26 psychiatric controls, and 26 normal controls using a radioenzymatic assay with phosphatidylcholine as precursor. Serum PLA2 activity was significantly higher in schizophrenics (p = 0.002) and other psychiatric (including substance abusing) patients (p = 0.032) than in normal controls. Enzyme activity did not differ between the schizophrenic patients and psychiatric controls. Fifty-one percent of the schizophrenics and 46% of psychiatric controls had PLA2 values above the highest value for normal controls. In the psychiatric control group higher than normal PLA2 activities were observed in all diagnostic categories, including major depression, bipolar disorder, posttraumatic stress disorder (PTSD), and substance abuse. In the context of others' findings of increased circulating PLA2 in infectious and inflammatory conditions, these increases must be viewed as disease nonspecific. The significance of these changes and their relationship to other acute-phase protein changes needs to be clarified in future research.

Plasma homovanillic acid in neuroleptic responsive and nonresponsive schizophrenics

Changes in plasma homovanillic acid (HVA) were investigated in neuroleptic responsive and nonresponsive schizophrenics in order to delineate parameters of dopamine regulation, which may underlie differences in neuroleptic responsivity. Nineteen schizophrenics were treated with haloperidol for 6 weeks. HVA was sampled at baseline, 24 hr after initial neuroleptic dose, and after 6 weeks of treatment. Subjects were pretreated with debrisoquin in order to reduce the peripheral production of HVA. The responders had an initial rise in HVA at 24 hr after first neuroleptic dose, followed by a decline back to baseline over the 6 weeks of treatment. The nonresponders' HVA failed to rise at 24 hr after first neuroleptic dose. At 6 weeks of treatment their HVA had fallen to significantly below baseline. Thus, a rise in HVA 24 hr after the first dose of neuroleptic predicted treatment response; a fall in HVA at 6 weeks to below pretreatment values was associated with neuroleptic nonresponse.

Vitamin E treatment of tardive dyskinesia

OBJECTIVE

The authors studied the effects of vitamin E treatment of tardive dyskinesia; earlier studies have produced contradictory results.

METHOD

Twenty-eight patients with tardive dyskinesia were treated in a double-blind, parallel-group comparison study of 8-12 weeks of treatment with vitamin E (1600 IU/day) or matching placebo capsules.

RESULTS

The Abnormal Involuntary Movement Scale scores of the patients treated with vitamin E improved significantly compared to the scores of the patients given placebo.

CONCLUSIONS

These results support earlier findings of the efficacy of vitamin E in treating tardive dyskinesia.

Negative symptoms and hypofrontality in chronic schizophrenia

Frontal lobe dysfunction is widely suspected to underlie negative symptoms of schizophrenia. This hypothesis is based largely on long-standing observations of the similarities between the effects of frontal lobe lesions and negative symptoms. However, there is little direct evidence specifically for such an association in schizophrenic patients. We measured the relationship between decreased relative prefrontal cortex glucose metabolism (hypofrontality) using positron emission tomography and evaluated the severity of negative symptoms in 20 chronic schizophrenics who underwent scanning while not receiving neuroleptic drugs. We found a close relationship between negative symptoms and prefrontal hypometabolism, particularly in the right dorsolateral convexity. This association was regionally specific. Furthermore, there was no evidence that this relationship was an artifact of age, cerebral atrophy, or severity of positive symptoms.

Efficacy of betaxolol in neuroleptic-induced akathisia

Betaxolol, a beta 1-selective antagonist, produced marked improvement in eight patients with neuroleptic-induced akathisia. No further improvement was seen with subsequent propranolol treatment. These findings, along with the results of prior studies of betaxolol and metoprolol, suggest that blockade of central beta 1-receptors may be sufficient for efficacy in akathisia.

Stability of resting deoxyglucose metabolic values in PET studies of schizophrenia

Positron emission tomography (PET) and the deoxyglucose method were used to determine the test-retest stability of regional cerebral glucose metabolism in 8 male schizophrenic patients and 11 normal control subjects, scanned twice under baseline (resting) conditions. Normal and schizophrenic subjects showed comparable stability of regional metabolism. When the regional values were scaled to compensate for the effects of changes in whole brain metabolism, the resulting mean regional changes were reduced to about 1-2% in both groups. This study demonstrates that the baseline resting state is an appropriate reference state for schizophrenic subjects in deoxyglucose PET experiments.

Disappearance of memory deficits in outpatient depressives responding to imipramine

We evaluated learning and memory in 50 depressed patients prior to and following 4 week treatment with imipramine compared to 21 normal controls tested at corresponding times. At baseline, the depressives did worse than normals on most memory tasks with the difficult memory tasks, regardless of store, modality or type of task best distinguishing between depressive and normal memory. Following imipramine treatment, responders performed better than nonresponders on the difficult memory tasks, and not significantly differently from controls on most tasks. This, as well as the fact that the responders improved to a greater degree than controls on most measures (in a few cases the difference was statistically significant) and the fact that at 4 weeks complete responders to imipramine did significantly better than partial responders to imipramine, indicates that relief from depression is highly related to improved memory functioning. The finding that complete responders to imipramine were not significantly worse than normal controls suggests that imipramine did not have significant adverse effects on memory.

Lack of efficacy of d-propranolol in neuroleptic-induced akathisia

d-Propranolol lacks clinically significant beta-adrenergic receptor blocking properties, but has the same membrane stabilizing effects as racemic (d,l) propranolol. To assess the role of beta-blockade versus membrane stabilization or other shared nonspecific effects in the therapeutic action of propranolol in neuroleptic-induced akathisia (NIA) we treated 11 patients with NIA in a crossover, double-blind study of d-propranolol versus placebo. Akathisia scores were unchanged after both d-propranolol and placebo. Eight patients were subsequently treated in a nonblind manner with racemic propranolol, with a significant reduction in akathisia scores. These findings suggest that beta-blockade, not membrane stabilization or other shared nonspecific effects, contributes to the efficacy of propranolol in NIA.

The prevalence of tardive dyskinesia

A total of 2250 subjects from psychiatric and geriatric settings was examined for abnormal involuntary movements by the same team of trained raters employing a standard examination technique and rating scale. "Spontaneous" dyskinesia rates were 1.3% among 400 healthy elderly people surveyed at senior citizens centers, 4.8% among medical geriatric inpatients and ranged from 0 to 2% among psychiatric patients never exposed to neuroleptics. For samples of neuroleptic-treated patients, prevalence rates ranged from 13.3% among patients at a voluntary psychiatric hospital to 36.1% among state hospital patients. Logistic regression analyses revealed a large effect of age on tardive dyskinesia prevalence and an interaction of age with sex. Among younger subjects, men had higher rates; among subjects over age 40, rates were higher for women. Edentulousness and presence of other neurological disorders were possible contributors to high rates for the elderly. Even with control for age, sex and duration of neuroleptic exposure, prevalence differed markedly across study site.

Disorders of decision in affective disease: an effect of beta-adrenergic dysfunction?

We investigated response bias (defined as the decision rule subjects adopt when uncertain) in two experiments using a variant of Signal Detection Theory (SDT) with the discrimination measure d'L and the bias measure CL, under which it is possible to independently evaluate discrimination and response bias. In the first experiment, manics, depressed subjects, and matched psychiatrically normal controls were tested with a recognition memory task with easier and more difficult components before and after 1 month of appropriate pharmacological treatment. This experiment showed that abnormally conservative bias was characteristic of depression and liberal (yea-saying) bias was found in mania regardless of severity of illness; discrimination deficits were found only when symptoms were severe. After treatment, aspects of discrimination worsened in both hypomanic and depressed nonresponders whereas response bias remained unchanged in these patients. In both groups of responders, improvements in response bias were more dramatic than improvements in discrimination. In the second experiment, psychiatrically normal hypertensives were tested with a Sternberg short-term memory scanning task on and off treatment with the centrally active beta-blocker propranolol. This experiment showed that treatment with propranolol modeled the bias deficit of depression; that is, bias became more conservative. Both sets of results suggest that disorders of decision may be modulated by beta-adrenergic function.

ECT and Parkinson's disease revisited: a "naturalistic" study

In an open study, seven patients with Parkinson's disease received ECT for major depression. Both the motor dysfunction and the mood impairment of these patients improved following an average of seven ECT sessions. Significant improvement in motor function occurred after only two treatments. All aspects of Parkinson's disease improved significantly after ECT. Older patients showed greater improvement in motor function. The authors conclude that the therapeutic utility of ECT in depressed and nondepressed patients with Parkinson's disease should be further evaluated.

Efficacy of low-dose metoprolol in neuroleptic-induced akathisia

Recent studies have shown that the beta-blockers can be effective treatments for neuroleptic-induced akathisia. However, the relative contributions of beta-1 versus beta-2 blockade to the therapeutic effect of beta-blockers remains unclear. We treated nine patients who had neuroleptic-induced akathisia with low doses (25-100 mg/day) of the beta-blocker metoprolol. At these doses metoprolol causes selective blockade of beta-1 receptors. Seven patients improved after metoprolol; no further substantial changes were seen after subsequent treatment with propranolol. This finding suggests that neuroleptic-induced akathisia can be improved by selective beta-1 blockade.

Dopamine blockade and clinical response: evidence for two biological subgroups of schizophrenia

Because CNS neuroleptic concentration cannot be directly measured in patients, the relation between clinical response and extent of dopamine receptor blockade is unknown. This relationship is critical in ascertaining whether nonresponse to neuroleptics is the result merely of inadequate CNS drug levels or of more basic biological differences in pathophysiology. Using [18F]N-methylspiroperidol and positron emission tomography, the authors assessed dopamine receptor occupancy in 10 schizophrenic patients before and after treatment with haloperidol. Responders and nonresponders had virtually identical indices of [18F]N-methylspiroperidol uptake after treatment, indicating that failure to respond clinically was not a function of neuroleptic uptake or binding in the CNS.

Neuroleptic augmentation with alprazolam: clinical effects and pharmacokinetic correlates

Alprazolam added to stable doses of neuroleptics in nine schizophrenic patients was associated with a 20%-30% mean reduction in positive and negative symptoms, although clinical response was variable and in some patients particularly brisk. The authors examined the possibilities of a pharmacokinetic effect of alprazolam on neuroleptic plasma levels and of a clinical effect of alprazolam. The modest increase in mean neuroleptic plasma levels did not correlate with clinical change, but those patients with the highest alprazolam plasma levels tended to show more robust clinical responses.

Effects of verapamil on tardive dyskinesia and psychosis in schizophrenic patients

Nine hospitalized schizophrenic patients with tardive dyskinesia were treated with the calcium-channel antagonist verapamil under single-blind conditions. The tardive dyskinesia and activation scores decreased, and the anxiety/depression scores increased. The changes were small but statistically significant.

Effects of a specific beta 2-receptor blocker in neuroleptic-induced akathisia

To assess the role of blockade of beta-receptor subpopulations in the treatment of neuroleptic-induced akathisia (NIA), the specific beta 2-antagonist ICI 118,551 was compared to placebo in a double-blind study. After a baseline evaluation on placebo, patients were treated with ICI 118,551 or placebo. Five of six patients treated with ICI 118,551 showed improvements in NIA, while only one of four patients improved on placebo. Patients were then treated openly with propranolol, a mixed beta 1, beta 2-antagonist. Compared to ICI 118,551, no further improvement on objective measures of akathisia was seen on propranolol. Mean subjective assessments of NIA declined on propranolol, but changes were variable and not statistically significant.

Neuroleptic-induced akathisia: a review

Neuroleptic-induced akathisia (NIA) is a relatively common side effect of neuroleptics, in which patients complain of a subjective sense of restlessness usually referable to the legs and have characteristic motor movements. This paper will review: 1) history of spontaneously occurring syndromes of pathologic restlessness and NIA, 2) the clinical significance of NIA, 3) issues concerning the diagnosis and quantification of NIA, 4) treatments of NIA and 5) possible future directions for research in this area. Special attention will be paid to newer treatments for this syndrome, specifically beta-blockers.

Preliminary studies of clonidine in psychotic patients

Twelve psychotic patients received a mean dose of 3.3 mg/day of clonidine. In four clonidine was the only treatment and in the remaining eight clonidine was superadded to a neuroleptic regimen after symptomatology was stable. Clonidine caused reduction of scores for both productive psychotic symptoms and anxiety. Negative symptoms were unaffected. These findings are discussed with respect to the small magnitude of the effects, questions as to specificity of the effects and methodologic limitations of this pilot study.

Serial [18F]N-methylspiroperidol PET studies to measure changes in antipsychotic drug D-2 receptor occupancy in schizophrenic patients

An indirect approach to the relationship among drug dose, plasma level, and the competition between a labeled neuroleptic drug [18F]N-methylspiroperidol (18F-NMS) for binding sites in striatal tissue in normal and schizophrenic subjects is described. The slope of the line plotting the ratio of activity in the striatum (As) to activity in the cerebellum (Ac) versus time up to 5 hr postinjection of 18F-NMS is taken as a marker of site occupancy. An inverse relation between labeled competitor uptake and drug plasma level has been demonstrated for the classes of antipsychotic drug studied. Striatal uptake studies showed a progressive increase in all subjects following drug withdrawal up to 156 hr postwithdrawal. Uptake and clearance of 18F-NMS in cerebellar tissue was not appreciably affected by antipsychotic medication or drug withdrawal.